Deficits in social cognition characterize many human psychiatric disorders, but the neural substrates of such deficits remain largely unknown. In fact, there is little certainty about the neural systems that normally subserve social cognition. This deficiency is largely due to the use of invasive methods and a lack of standardized behavioral testing paradigms that probe components of social cognition, such as social perception and social motivation. During the proposed funding period, I will obtain additional training and expertise by addressing these deficits. During the K99 phase, I will measure cerebral glucose metabolism, a correlate of neural activity, using high-resolution positron emission tomography (microPET). Two video presentations will be created; one depicting a variety of social interactions and the other with no social content. MicroPET data will be acquired after subjects view each video to identify neural regions preferentially engaged during the perception of visual social signals. A second study will investigate the neural correlates of social motivation. Some adult animals typically forego juice rewards to view pictures of salient social signals (i.e., female sexual swellings), but not to view pictures of lower-ranked animals or objects. Comparison of microPET data acquired after each of these three conditions will identify brain regions involved in directing behavior towards socially relevant information. Both studies will use noninvasive eye tracking techniques to measure visual attention to videos or choices of social pictures versus juice rewards. In the subsequent ROO phase, I will implement the skills and behavioral tasks developed during the K99 phase to investigate how cerebral metabolism differs in subjects raised under atypical conditions (i.e., nursery-reared) or for animals that exhibit maladaptive social behavior. Relevance to Public Health: Social behavior deficits are prevalent in many human psychiatric disorders, such as autism, social anxiety disorder and depression. However, effective treatments remain elusive because little is known about how the normal brain processes social information and selects appropriate social behaviors. The goal of these studies is to develop new, noninvasive methods for identifying: brain areas subserving these abilities.